1. Field of the Invention
The present invention relates to a compound archery bow for shooting an arrow and more particularly to an improved archery bow featuring draw force let off, distortion free bow tips and an highly effective and efficient archery bow.
2. Prior Art
Compound bows are well known to those skilled in the art. Such bows utilize eccentric cams, wheels and pulleys on the bow limb tips about which a bow string is sheaved such that when the bow string is drawn, the draw force on the bow string initially rapidly builds up to its maximum intended limit and thereafter noticeably falls off as the bow string is fully drawn. The advantage and purpose of such an operation are well known to those skilled in the art and such description and operation may be found in patent to Allen, U.S. Pat. No. 3,486,495; patent to Jenning, U.S. Pat. No. 4,241,715; patent to Roelle, U.S. Pat. No. 4,333,443 and patent to Simonds U.S. Pat. No. 4,438,756. While such prior art archery bows have worked satisfactorily and have improved and advanced the art, there still are pressing problems encountered with the use of eccentric cams, wheels and pulleys rotating on a shaft on the bow tips of the archery bow since the eccentric cams, wheels and pulleys add friction and inertia to the bow tip. The aforesaid prior art compound bows utilize forces which act along a line that does not pass through the center of rotation of the eccentric cams, wheels or pulleys to cause a moment about the center of rotation of the cams, wheels or pulleys. A moment about the eccentric cams, wheels or pulleys is equal to the force multiplied by the perpendicular distance from the line of action of the force to the center of rotation. In effect, clockwise moments about the center of rotation must be equal to the counter-clockwise moments for the bowstring to be in a state of equilibrium. While utilizing this basic principal in the aforesaid issued patents, a major problem is that the bowstring is sheaved on the cams, wheels and pulleys and provide such as eccentric loading on the bow tips and unduly high inertia on the bow tips of the archery bow. Further, such prior art also utilized cross cables which are generally proximal to the bowstring and interfere with an arrow being shot from the archery bow. Attempts have been made to configure the eccentric cams, wheels or pulleys with grooves which tend to place the bowstring in a non-interfering position relative to the cross cables. While these attempts place the bowstring in a non-interfering position, the added grooves for guarding the bowstring away from the cross cables do create another problem in that the bowstring must travel a greater distance over the grooves on the cams, wheels and pulleys to solve this problem.
Accordingly, there is a pressing need for a relatively simple, inexpensive, efficient improved archery bow which eliminates cams, wheels and pulleys and the aforesaid problems of eccentric loading, high inertia and friction in the bow tips and the utilization of moments about the axis of rotation at the bow tips in the clockwise and counter-clockwise directions.